A novel analytical model for intensity modulated and direct detected multiple-input–multiple-output system with time related zero forcing equalization over multimode fiber

In this paper, basing on tap delay lines filter model and model spatial coupling theory, we build up a novel analytical model for an intensity modulated and direct detected multiple-input–multiple-output (IM-DDMIMO) system over multimode fiber. At the receiver side, time related zero forcing (ZF) equalization was used to recover signals. With this model, we theoretically and by simulation analyzed a 2 × 2 multimode fiber MIMO system utilizing offset launching scheme. It's found that two received streams can be well recovered by equalization. Compared with traditional single-input–single-output (SISO) system, such 2 × 2MIMO system can provide at least 5 dB Bit error rate (BER) performance improvement.